feat: edit existing messages for workflow run updates

src/core/dispatch.ts

@@ -6,6 +6,7 @@ import { loadTranslations, type Translations } from "../lib/i18n";
 import { recordSend } from "../lib/send-log";
 import { loadGroups, groupAcceptsOwners } from "../web/groups";
 import { getDriver } from "../drivers";
+import type { SendResult } from "../drivers/types";
 
 export async function dispatchEvent(config: Config, event: WebhookEvent, env: Env): Promise<void> {
   const langs = [...new Set(config.routes.map((r) => r.lang ?? "en"))];
@@ -78,7 +79,47 @@ export async function dispatchEvent(config: Config, event: WebhookEvent, env: En
         const started = Date.now();
         try {
           const driver = getDriver(target);
-          const result = await driver.send(message, target, env);
+          let result: SendResult;
+          if (message.updateKey) {
+            const kvKey = `msg:${route.id}:${message.updateKey}:${targetStr}`;
+            const existingId = await env.KV.get(kvKey);
+            if (existingId) {
+              result = await driver.edit(message, target, env, existingId);
+              if (result.ok) {
+                await recordSend(env.DB, {
+                  ...base,
+                  ok: true,
+                  status: result.status,
+                  messageId: existingId,
+                  platform: driver.id,
+                  attempts: result.attempts,
+                  durationMs: Date.now() - started,
+                  errorCode: result.errorCode,
+                });
+                continue;
+              }
+              if (/not modified/i.test(result.error ?? "")) {
+                await recordSend(env.DB, {
+                  ...base,
+                  ok: true,
+                  status: result.status,
+                  messageId: existingId,
+                  platform: driver.id,
+                  attempts: result.attempts,
+                  durationMs: Date.now() - started,
+                  errorCode: result.errorCode,
+                });
+                continue;
+              }
+              await env.KV.delete(kvKey);
+            }
+            result = await driver.send(message, target, env);
+            if (result.ok && result.messageId) {
+              await env.KV.put(kvKey, result.messageId, { expirationTtl: 604800 });
+            }
+          } else {
+            result = await driver.send(message, target, env);
+          }
           const durationMs = Date.now() - started;
           if (!result.ok) throw new Error(result.error ?? "Send failed");
           await recordSend(env.DB, {

src/drivers/discord/index.ts

@@ -1,6 +1,6 @@
 import type { RouteTarget, Env, NeutralMessage } from "../../types";
 import type { PlatformDriver, SendResult } from "../types";
-import { sendMessage } from "./rest";
+import { sendMessage, editMessage } from "./rest";
 import { renderNeutralMessage } from "./render";
 
 export class DiscordDriver implements PlatformDriver {
@@ -14,4 +14,18 @@ export class DiscordDriver implements PlatformDriver {
     const token = env.DISCORD_TOKEN ?? "";
     return sendMessage(token, channelId, renderNeutralMessage(message), target.threadId);
   }
+
+  async edit(
+    message: NeutralMessage,
+    target: RouteTarget,
+    env: Env,
+    messageId: string,
+  ): Promise<SendResult> {
+    const channelId = target.channelId ?? "";
+    if (!channelId) {
+      return { ok: false, error: "target.channelId is required", errorCode: "NO_TARGET" };
+    }
+    const token = env.DISCORD_TOKEN ?? "";
+    return editMessage(token, channelId, messageId, renderNeutralMessage(message), target.threadId);
+  }
 }

src/drivers/discord/rest.ts

@@ -7,20 +7,17 @@ interface DiscordMessage {
   id?: string;
 }
 
-export async function sendMessage(
+async function request(
+  url: string,
+  method: string,
   token: string,
-  channelId: string,
   message: unknown,
-  threadId?: string,
+  channelId: string,
 ): Promise<SendResult> {
-  const url = threadId
-    ? `${DISCORD_API}/channels/${threadId}/messages`
-    : `${DISCORD_API}/channels/${channelId}/messages`;
-
   for (let attempt = 0; attempt < 3; attempt++) {
     try {
       const res = await fetch(url, {
-        method: "POST",
+        method,
         headers: {
           Authorization: `Bot ${token}`,
           "Content-Type": "application/json",
@@ -80,3 +77,27 @@ export async function sendMessage(
 
   return { ok: false, error: "Max retries exceeded", errorCode: "RETRIES", attempts: 3 };
 }
+
+export async function sendMessage(
+  token: string,
+  channelId: string,
+  message: unknown,
+  threadId?: string,
+): Promise<SendResult> {
+  const url = threadId
+    ? `${DISCORD_API}/channels/${threadId}/messages`
+    : `${DISCORD_API}/channels/${channelId}/messages`;
+  return request(url, "POST", token, message, channelId);
+}
+
+export async function editMessage(
+  token: string,
+  channelId: string,
+  messageId: string,
+  message: unknown,
+  threadId?: string,
+): Promise<SendResult> {
+  const base = threadId ?? channelId;
+  const url = `${DISCORD_API}/channels/${base}/messages/${messageId}`;
+  return request(url, "PATCH", token, message, channelId);
+}

src/drivers/telegram/index.ts

@@ -1,6 +1,6 @@
 import type { RouteTarget, Env, NeutralMessage } from "../../types";
 import type { PlatformDriver, SendResult } from "../types";
-import { sendMessage, sendPhoto } from "./rest";
+import { sendMessage, sendPhoto, editMessageText, editMessageCaption } from "./rest";
 import { renderNeutralMessage } from "./render";
 
 function smallAvatar(url: string): string {
@@ -8,6 +8,14 @@ function smallAvatar(url: string): string {
   return `${url}${sep}s=64`;
 }
 
+function richHeaderUrl(message: NeutralMessage, avatar: string, host: string): string {
+  const params = new URLSearchParams();
+  if (message.author?.name) params.set("title", message.author.name);
+  if (message.title) params.set("content", message.title);
+  params.set("avatar", avatar);
+  return `${host.replace(/\/+$/, "")}/api/richheader?${params.toString()}`;
+}
+
 export class TelegramDriver implements PlatformDriver {
   readonly id = "telegram";
 
@@ -21,11 +29,7 @@ export class TelegramDriver implements PlatformDriver {
     const avatar = message.author?.iconUrl;
     const richHeaderHost = env.TELEGRAM_RICH_HEADER_HOST ?? env.BASE_URL;
     if (avatar && richHeaderHost) {
-      const params = new URLSearchParams();
-      if (message.author?.name) params.set("title", message.author.name);
-      if (message.title) params.set("content", message.title);
-      params.set("avatar", avatar);
-      const rhUrl = `${richHeaderHost.replace(/\/+$/, "")}/api/richheader?${params.toString()}`;
+      const rhUrl = richHeaderUrl(message, avatar, richHeaderHost);
       return sendMessage(token, chatId, text, target.topicId, rhUrl);
     }
     if (avatar) {
@@ -33,4 +37,28 @@ export class TelegramDriver implements PlatformDriver {
     }
     return sendMessage(token, chatId, text, target.topicId);
   }
+
+  async edit(
+    message: NeutralMessage,
+    target: RouteTarget,
+    env: Env,
+    messageId: string,
+  ): Promise<SendResult> {
+    const chatId = target.chatId ?? "";
+    if (!chatId) {
+      return { ok: false, error: "target.chatId is required", errorCode: "NO_TARGET" };
+    }
+    const token = env.TELEGRAM_TOKEN ?? "";
+    const text = renderNeutralMessage(message);
+    const avatar = message.author?.iconUrl;
+    const richHeaderHost = env.TELEGRAM_RICH_HEADER_HOST ?? env.BASE_URL;
+    if (avatar && richHeaderHost) {
+      const rhUrl = richHeaderUrl(message, avatar, richHeaderHost);
+      return editMessageText(token, chatId, messageId, text, target.topicId, rhUrl);
+    }
+    if (avatar) {
+      return editMessageCaption(token, chatId, messageId, text, target.topicId);
+    }
+    return editMessageText(token, chatId, messageId, text, target.topicId);
+  }
 }

src/drivers/telegram/rest.ts

@@ -134,3 +134,56 @@ export async function sendPhoto(
   }
   return post(token, "sendPhoto", body, chatId);
 }
+
+export async function editMessageText(
+  token: string,
+  chatId: string,
+  messageId: string,
+  text: string,
+  topicId?: string,
+  linkPreviewUrl?: string,
+): Promise<SendResult> {
+  if (!token) {
+    return { ok: false, error: "TELEGRAM_TOKEN not configured", errorCode: "NO_TOKEN" };
+  }
+  const body: Record<string, unknown> = {
+    chat_id: chatId,
+    message_id: messageId,
+    text,
+    parse_mode: "HTML",
+    disable_web_page_preview: !linkPreviewUrl,
+  };
+  if (linkPreviewUrl) {
+    body.link_preview_options = {
+      url: linkPreviewUrl,
+      prefer_small_media: true,
+      show_above_text: true,
+    };
+  }
+  if (topicId) {
+    body.message_thread_id = Number(topicId);
+  }
+  return post(token, "editMessageText", body, chatId);
+}
+
+export async function editMessageCaption(
+  token: string,
+  chatId: string,
+  messageId: string,
+  caption: string,
+  topicId?: string,
+): Promise<SendResult> {
+  if (!token) {
+    return { ok: false, error: "TELEGRAM_TOKEN not configured", errorCode: "NO_TOKEN" };
+  }
+  const body: Record<string, unknown> = {
+    chat_id: chatId,
+    message_id: messageId,
+    caption,
+    parse_mode: "HTML",
+  };
+  if (topicId) {
+    body.message_thread_id = Number(topicId);
+  }
+  return post(token, "editMessageCaption", body, chatId);
+}

src/drivers/types.ts

@@ -12,4 +12,9 @@ export interface SendResult {
 export interface PlatformDriver {
   readonly id: string;
   send(message: NeutralMessage, target: RouteTarget, env: Env): Promise<SendResult>;
+  /**
+   * Edit an already-sent message in place (e.g. workflow run progress updates).
+   * Must be implemented by drivers that support message updates.
+   */
+  edit(message: NeutralMessage, target: RouteTarget, env: Env, messageId: string): Promise<SendResult>;
 }

src/formatters/workflow.ts

@@ -100,6 +100,7 @@ export function formatWorkflowRun(
   showEmoji: boolean,
 ): NeutralMessage {
   const workflow = payload.workflow_run as {
+    id?: number;
     name?: string;
     conclusion?: string;
     html_url?: string;
@@ -183,6 +184,8 @@ export function formatWorkflowRun(
       url: workflow.html_url,
       color: GITHUB_COLORS[colorKey],
       fields,
+      updateKey:
+        repo && workflow.id != null ? `workflow_run:${repo}:${workflow.id}` : undefined,
     },
     t,
     repo,

src/types.ts

@@ -124,6 +124,12 @@ export interface NeutralMessage {
   footer?: string;
   timestamp?: string;
   actions?: NeutralAction[];
+  /**
+   * Stable key identifying a message chain that should be updated in place
+   * (e.g. workflow run progress). When set, subsequent events edit the
+   * previously sent message instead of sending a new one.
+   */
+  updateKey?: string;
 }
 
 export interface FormattedMessage {